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Let's be careful how we use unified enrollment systems

Getty Images/Madrolly

Mike McShane

September 26, 2018

In the beloved 1990s British television series Father Ted, Ted ruins a Rover 213 that was supposed to be an auction prize to raise money to fix the Craggy Island parochial house roof. After spotting a dent, Ted tries to hammer it out. Hammering out the small dent creates another dent, which he then tries to hammer out, and by the time he’s done, he’s destroyed the entire car.

It is a great visualization of the bad consequences of good intentions.

Reading recent stories about the trials and tribulations of unified enrollment systems reminds me of Ted’s misadventure. Central planners tinker and tinker, causing new problems for each one they solve. Perhaps they should stop before they’ve wrecked the whole thing.

For those who may be unfamiliar, unified enrollment systems were created for cities that have a lot of potential school choices for families. Rather than admit students on a first come first served basis or have each and every school manage its own enrollment and hold its own lottery, a central system is created that allows families to rank their preferences. These preferences are fed into a computer algorithm that, in theory, should maximize the number of children getting into the schools they prefer.

Unified enrollment systems are responding to real problems. Making families enter a dozen or more lotteries to find a seat for their child in a charter school is cumbersome. Some public magnet schools get filled on a first-come-first-served basis with an application process is hard to divine. Making the process fair and transparent is important to ensure that schools that are ostensibly open enrollment are in fact open enrollment.

That said, unified enrollment systems can also be a one-stop shop for central planners looking to impose their own visions of what schools should look like. What is often left out of discussions about unified enrollment systems is that more than just parental preferences can be loaded into the algorithm. Various preferences are included that can increase or decrease a student’s likelihood of getting into a school of their choice. Some of these make sense, for example, granting preference to students who already have a sibling in the school. But the more and more tweaks get added into the system, the less and less it reflects parental choices, and the more it reflects what central authorities want schools to look like.

A recent story out of Boston illustrates this well. Researchers examining the city’s enrollment system (for its traditional public schools) found that it was exacerbating segregation, one of the very problems it was created to solve. How could this be?

The designers of Boston’s enrollment system built in rules that created that outcome. The algorithm preferences students who live close to a school. Since more sought after schools were more likely to be located in wealthier and whiter neighborhoods, wealthier and whiter students had the first crack at getting into them. Segregation was exacerbated.

But Boston is not alone. New Orleans’s OneApp system has generally received high praise, but this year it had the lowest rate of students matching to one of their top three choices since its introduction. In response to different and at time competing demands, the OneApp system has all kinds of preferences built in that shape the eventual outcome. Its opacity is driving parents nuts.

I worry that we’re going to see more of this. Much of what I read about unified enrollment systems is about how to tinker with these systems to produce some desired outcome. How can we change the algorithm to promote integration? How can we change the algorithm to shorten transportation time? How can we “nudge” families into schools with higher test scores?

Each of these goals is laudable, but each rests upon judgment calls. What is the ideal racial makeup of a school? What is the ideal travel time? How do we weigh school performance versus the host of other things that parents might want from schools? They become more complex the more variables you add. How do we balance integration and travel times? Travel times and school performance? Each tweak in one part of the system undermines the tweaks made in the other part of the system.

Dealing with these fraught and value-laden debates via algorithm might be the worst way to handle them. Changes occur outside of public view. Without access to data or advanced training in statistics, just how much one facet is valued over another is completely unclear. Families are simply expected to accept the results and trust the algorithm. They have no reason to do so.

I’m not against common application systems or other mechanisms to reduce the frictions in matching children to schools they want to attend. But, I, and other policymakers and social reformers have to resist the temptation to manipulate unified enrollment systems to reach whatever our desired ends are. Use these systems to make school assignment fairer and level the playing field when it comes to applying to schools. Use them to make parents’ lives easier. Don’t use them to try and engineer the ideal school system. We’ll just wreck the car.